Detergent compositions



United States Patent DETERGENT COMPOSITIONS Allen H. Lewis and Richard D. Stayner, Berkeley, Calif.,

assignors to California Research Corporation, San Francisco, Califi, a corporation of Delaware No Drawing. Application February 2, 1954, Serial No. 407,818

4 Claims. (Cl. 252-161) The present invention relates to anionic synthetic detergent compositions. More particularly, it relates to detergent compositions containing an alkyl sulfate as the active organic detergent ingredient thereof and capable of producing dense, stable and persistent foams when dissolved in water to formconventional household or commercial laundering solutions.

Small scale users of synthetic anionic detergents prefer detergent products capable of producing substantial lather or foam, particularly in view of the fact that formation of a copious persistent foam is often accepted by the user as an indication of the proper quantity of detergent to be employed in making up wash solutions.

Customer acceptance of synthetic anionic detergents for laundry uses, especially in the home, has been rather slow: (1) because the foam produced by these detergents and their mixtures lacks stability and has an unsatisfactory lacy texture, as contrasted with the uniformly small-sized bubbles and heavy-bodied, cream-like consistency of conventional soapsuds; and (2) because the persistence of the foam, in the presence of soil and under conditions of agitation, produced by a number of otherwise efficient detergents, in particular of the alkyl sulfate or mixed alkyl sulfate-alkyl benzene sulfonate type is inadequate.

The various additives suggested in the art for the purpose of improving the foam characteristics of the aforementioned alkyl sulfate and mixed alkyl sulfate-alkyl benzene sulfonate detergents are often found to be incapable of insuring formation of persistent foam without impairing at the same time the detergency of the composition, or without adversely affecting some other properties thereof in one way or another. Thus, while the addition of lauryl alcohol improves the sudsing performance, a fatty odor is imparted by the presence of this alcohol to the finished dried detergent particles and, furthermore, a considerable proportion of the alcohol additive is lost in spray-drying of the neutralized slurries of alkyl sulfates and mixed "ice produce a copious stable foam of good quality, capable of persistence under the conditions of agitation in the presence of soiled laundry in the tub of a washing machine.

As indicated hereinabove, the water-soluble salts of n-alkyl sulfuric acids suitable for the preparation of the detergent compositions of our invention are salts of alkyl sulfuric acids, fl-hydroxyalkyl sulfuric acids and -hydroxyalkyl sulfuric acids, which contain from 8 to 18 carbon atoms in the hydrophobic alkyl group, and in which the hydrophilic group occupies the terminal posi tion on the carbon chain. These salts include among their number sodium, potassium, magnesium, ammonium, alkyl ammonium and alkylol ammonium salts. As a practical matter, however, sodium salts of Cs-C1s primary alkyl sulfuric acids are usually employed, those containing from 14 to 18 carbon atoms in the alkyl chain being preferred on account of the lower cost and immediate availability. These salts may be prepared by any known suitable method, e. 'g., by any or" the methods of sulfation of straight-chain C8-C1s aliphatic alcohols, described at pages 53 to 58 of the book Surface-Active Agents, by A. M. Schwartz and J. W. Perry (Interscience publishers, 1949, New York), followed by neutralization to obtain a watersoluble salt, and by drying this salt to the desired particleform.

In addition, we have found that as much as by weight of the Cs-Cra alkyl sulfate (sulfated alcohol) in the detergent composition may be replaced by a C9-C18 monoalkyl benzene sulfonate detergent, without affecting adversely the beneficial action of the para-n-acylphenol additive on the foam properties of the composition. The terms Cs-C1a alkyl sulfate and Ce-C18 monoalkyl benzene sulfonate in accordance with the established usage of the detergent art designate detergent water-soluble salts of Cs-Cis alkyl sulfuric acids and C9C1a monoalkyl benzene sulfonic acids. Because of their lesser cost and availability, sodium salts of the aforementioned organic sulfuric and sulfonic acids are usually employed, although water-soluble salts other than those of sodium may be employed whenever required by the particular washing or cleaning application.

The water-soluble salts of monoalkyl benzene sulfonic acids, employed in the preparation of the detergent compositions of our invention, are those containing from 9 to 18 carbon atoms, and preferably from 12 to 15 carbon atoms, in the alkyl chain, and include in their number sodium, potassium, magnesium, ammonium, alkyl ammonium or alkylol ammonium salts, although as a practical matter sodium salts are preferably employed. These salts are prepared by any of the several methods disclosed in the art, e. g., by starting with the condensation of propylene polymers and benzene as shown in U. S. Patent No. 2,477,383, issued to A. H. Lewis, or with the chlorination of a kerosene fraction boiling from 205 to 245 0, followed by the reaction of the resulting keryl chloride with benzene as shown in the U. S. Patent No. 2,218,472 issued to Kyrides. The resulting alkyl benzene stock produced by either technique is then sulfonated, and the sulfonic acid in the sulfonation reaction mixture is separated from the unreacted sulfuric acid. Thereupon after incorporating builders and other additives, if such may be desired, the neutralized slurry may be reduced to the particle-form by conventional drying techniques (spray-drying or drum-drying).

When aqueous solutions of detergent compositions containing detergent Cs-Cis alkyl sulfates or a mixture of detergent C8-Cl8 alkyl sulfates and 09-018 monoalkyl benzene sulfonates in the weight ratio from 1:1 to 1:6, and, furthermore, containing from about to about 50% by weight of para-n-acylphenol having from 8 to 16 and preferably from 10 to 14 carbon atoms in its acyl portion (based on the weight of the alkyl sulfate), are employed to wash fabrics in dilute concentrations in water (from 0.1 to 0.4%), in accordance with the conventional laundering practice, they produce a rich creamlike foam of densely agglomerated small bubbles. This foam retains its stability for relatively long periods of time, both under static conditions and under conditions of agitation in the presence of soil in the Washing machine throughout the length of the Washing cycle, i. e., as long as minutes and frequently longer. Furthermore, the detergency of the wash solutions containing these improved detergent compositions is not adversely affected by the presence of the foam-improving para-n-acylphenol additive.

It is well known that the detergent action of alkyl aryl sulfonates and alkyl sulfates is generally improved by the addition of water-soluble inorganic electrolyte salts or builders. These detergency builders added to detergent compositions exert a number of beneficial effects on the properties and actions of the detergent composition. For instance, they neutralize the acid soil, deflocculate (suspend) the soil and prevent its redeposition, sequester magnesium and calcium ions from hard water, aid micelle formation, etc. Whatever be the particular etfect of a specific detergent builder on the properties of alkyl benzyl sulfonates and alkyl sulfates in detergent compositions, all builders contribute to enhance the over-all washing efiiciency of detergent compositions,

We have found that the presence of water-soluble, alkaline, electrolyte salts of weak inorganic acids, e. g., carbonates, silicates, phosphates and borates, and of water-soluble, neutral, electrolyte salts of strong inorganic acids, e. g., sulfates and chlorides, as detergent (detergency) builders in the aforedescribed mixtures of alkyl sulfates and alkyl benzene sulfonates, in amounts ranging from 60 to 90% by weight of the total solids in a particular detergent composition, does in no way interfere with the improvement in foam characteristics thereof, brought about by the introduction of para-n-acylphenol additive in accordance with our invention. Although any of the Water-soluble alkaline and neutral inorganic electrolyte salt builders may be used in the formulations prepared in accordance with the present invention, inorganic sodium salt builders are usually employed, particularly in view of the general preference due to economic reasons for sodium salts of alkyl sulfuric and alkyl benzene sulfonic acids as active organic components of detergent formulations. These inorganic sodium salt builders for alkyl sulfate and alkyl benzene sulfonate detergents include sodium carbonates, sodium silicates, sodium polyphosphates, tetrasodium pyrophosphate, borax, sodium sulfate, sodium chloride, etc.

The para-aeylphenol foam-improving agent containing a straight chain of 8 to 16 carbon atoms and preferably from 10 to 14 carbon atoms in its acyl portion is prepared by any of the methods known in the art, e. g., by Friedel- Crafts acylation, described in the Journal of Organic Chemistry, vol. 5 (1945), at pages 165 and 645.

In general, all pure, straight-chain saturated Caz-C15 fatty acids derived from any suitable source of organic materials, e. g., from coconut oil, tallow, soybean oil, cottonseed oil and the like, as well as mixtures of such acids can be employed to prepare the p-acyl phenols for use in the detergent formulations of our invention. In

fact, fatty acid mixtures containing up to 30% by weight of stearic acid may be employed to prepare an effective mixed p-acyl phenol foam-improving agent. These materials are available in the trade under the name Pressed Stearic Acid and generally contain from about 45 to by weight of palmitic acid, from about 50 to about 20% by weight of stearic acid, the balance to make up by weight being fatty acids such as myristic, oleic, and linoleic. However, mixtures of fatty acids containing not more than 16 carbon atoms, namely mixtures of palmitic, myristic, lauric, capric and caprylic acids are preferred as initial materials for the preparation of pacyl phenol foam-improving agents. The Ca-Cie p-acyl phenols and their mixtures prepared from these materials are found to secure enhancement of foam properties. When the detergent formulations containing these pacyl phenols are employed for laundering purposes at temperatures ranging from 100 to F. in the tub of a washing machine, those formulations which contain p-acyl phenols with 10 to 14 carbon atoms in the acyl group are found to be particularly effective in enhancing and stabilizing foam. At higher Washing temperatures than in the 100 to 150 F. range, namely from 150 to 212 F., the higher molecular weight p-acyl phenols such as palmityl phenol are found to be also satisfactory for the purpose of improving the foam performance.

As contrasted with the previously mentioned lauryl alcohol foam-improving additive, para-n-acylphenols employed in the detergent compositions of our invention are practically odorless and can be efiectively spray-dried because of their low volatility. Furthermore, they are responsible for better foam persistence when hard water solutions (e. g., 300 p. p. m. of Ca-Mg hardness) are employed for washing. The lauryl alcohol additive is, on the contrary, ineffective in hard water solutions of alkyl sulfate detergents and mixed alkyl sulfate and monoalkyl benzene sulfonate detergents. It is to be noted that small amounts of unsulfated fatty alcohols, which are commonly present in sulfated alcohol compositions, do not adversely affect the foam performance achieved by the employment of para-n-acylphenols in the detergent compositions of our invention.

Although the para-n-acylphenol additives effectively enhance foam persistence of the detergent compositions containing C8-C18 n-alkyl sulfates (sulfated alcohols) 'as the detergent component, particularly in the case of 'alkyl sulfates derived from coconut fatty acids and containing on the average from about 45 to 55% by weight of lauryl sulfate, when C14-C1s alkyl sulfates, e. g., those derived from hydrogenated tallow and containing an average of from 60 to 70% by weight of C18 alkyl sulfates, are employed as active ingredients of our improved detergent compositions, the volume of foam produced by dilute aqueous wash solutions of these compositions is not sufiiciently large. We have found that when a portion (up to 85% by weight) of (311-018 alkyl sulfates, derived from hydrogenated fatty acids of tallow, cottonseed oil, soybean oil or the like organic materials, is replaced by C9-C1a monoalkyl benzene sulfonates, as mentioned hereinbefore, the foam volume of corresponding wash solutions can be substantially enhanced to compare favorably with the volume of foam obtained with soap; and that, owing to the presence of the para-n-acylphenol additive, this foam will possess excellent quality and persistence under conditions of agitation in the presence of soil. This is an important finding, considering the fluctuating prices and recurring scarcity of coconut oil and its fatty acids, as compared to the availability and low cost of tallow and fatty acids derived therefrom.

The additives other than the detergent builders comprise various compatible anti-caking compounds, optical bleaches, perfume, coloring agents (if required) and skin emollients such as various N-alky] glycines and diglycines. Sodium carboxymethyl cellulose and sodium celluronates may also be employed and act not only as extenders, but also exert a marked action in preventing redeposition of the soil. These various additives are employed in amounts readily determinable by those skilled in the art to suit the requirements of each particular application. Usually they constitute not more than 5% of the total weight of solids in the final detergent formulation.

Whether the detergent compositions of our invention are to contain only the monoalkyl sulfate as the organic detergent component thereof or whether the monoalkyl sulfate is to be used with an admixture of monoalkyl benzene sulfonate, it is preferred to prepare these compositions by blending (mixing) the active organic ingredients with the para-n-acylphenol foam-improving agent, detergent builders and other additions in the solution or slurry stage and then to dry the resulting mixture so as to insure a substantially uniform distribution of all ingredients within each particle. It is particularly preferred, when C14.C1s aliphatic alcohols derived from hydrogenated tallow fatty acids are available for the production of the alkyl sulfate detergent ingredient of mixed alkyl sulfate-alkyl benzene sulfonate detergent composition of our invention, to sulfonate a suitable alkyl benzene stock with an excess of concentrated (98-l00%) sulfuric acid, or 22% oleum, and then to add molten or flaked aliphatic alcohols derived from hydrogenated tallow fatty acids into the sulfonation reaction mixture to produce the desired alkyl sulfuric acids. Details of alkyl benzene sulfonation are described in the bulletin entitled Alkane-Product and Processing Information, published by Gronite Chemical Company of San Francisco, California, in 1950. In all events, the quantity of the sulfonating agent required for the preparation of the mixture of alkyl benzene sulfonic and alkyl sulfuric acids is governed by the desired weight ratio of detergent alkyl sulfate to alkyl benzene sulfonate in the ultimate neutralized product. The mixture of alkyl benzene sulfonic and alkyl sulfuric acids is neutralized with aqueous NaOH, NazCOs or other suitable neutralizing agent. The resulting neutralized slurry is then blended with the para n acylphenol foam improving agent, detergent builders and other additives, and the blend is dried to the desired solid particle-form. If necessary, the blend may be processed by an appropriate drying (evaporation) technique to a paste, or is diluted in order to be sold as a liquid concentrate.

A series of foam-evaluation bench tests was carried out in the laboratory, employing dilute aqueous solutions of dried particulate detergent formulations prepared in accordance with the invention in concentrations rang ing from 0.1 to 0.4%. In a particular representative test series, each 100 parts by weight of the built detergent formulation employed for making up test solutions contained as its active detergent portion from 20 to 22 parts by weight of a mixture of sodium alkyl sulfate and sodium monoalkyl benzene sulfonate, including the paran-acylphenol foam-improving agent. The weight ratio of the alkyl sulfate component to the monoalkyl benzene sulfonate component ranged from 1:1 to 1:6, and the amounts of para-n-acylphenol agent were in the range from 5 to 50% by weight of the alkyl sulfate component. The sodium alkyl sulfate component was prepared by neutralizing sulfated Cur-C13 fatty alcohols derived from hydrogenated tallow fatty acids by known procedures. The alkyl chains in these organic sulfates contained from 14 to 18 carbon atoms, the major proportion (60-70%) being C18 alkyl sulfates.

The sodium monoalkyl benzene sulfonate component was prepared by alkylating benzene with a mixture of pentamers and tetramers of propylene, sulfonating the resulting Ora-C15 monoalkyl benzene product and neutralizing in accordance with the aforementioned disclosure of U. S. Patent 2,477,383. As the representative para-nacylphenol foam-improving agent, para-laurophenol (phydroxylaurophenone) was used in the majority of the tests, unless otherwise indicated.

Detergent builders were present in the following amounts: 30 parts by weight of sodium tripolyphosphate; 20 parts by weight of tetrasodium pyrophosphate; 5 parts by weight of liquid sodium silicate (known as N grade in the trade and characterized by a sodia to silica ratio of 123.2); the remainder of the builder portion of the composition being tested was essentially sodium sulfate.

The particulate detergent formulations were dissolved in soft water (50 p. p. m. of Ca-Mg hardness) at F. to make up 500 ml. of 0.15% solution in a 2 liter beaker. The test solutions were agitated with the aid of a propeller-type stirrer for one minute and then allowed to stand for one minute, whereupon foam heights in millimeters were measured. 15 minutes after the agitation was terminated, the foam heights were measured again, and the stability and quality of the foam were ascertained. Foam stability was rated by observing the rate of foam decay under mechanical stress, as by blowing on a small volume of foam gently with air. In the case of unstable foam this procedure resulted in a rapid collapse of foam bubbles. Quality of the foam, i. e., the size of its bubbles, and the feel or the body thereof, was also observed and rated. Foams of good quality have uniformly small-sized bubbles and a high bulk viscosity. They are white and opaque. Poor quality is manifested by uniformly large-sized foam bubbles, a low bulk viscosity, and a tendency towards laciness. These foams are more transparent and gray in color. Ratings of fair were assigned to foams of intermediate stability and quality.

A parallel series of tests runs, using the same dilute (0.15%) aqueous solutions of detergent formulations as in the bench" tests, but both in soft (50 p. p. m.) and hard water (500 p. p. m. Ca-Mg), was carried out to ascertain persistence of the foam under the conditions of operation, prevailing in the commonly used nonautomati c agitator-type domestic washing machines. A conventional quantity of the wash solution was added into the bowl of the machine, followed by a load of soiled cotton towels. The contents were agitated in each test run under substantially identical conditions of operation and temperature (120-130" F.), approximating the conditions and temperature of the regular laundering practice. The foam was observed at regular intervals and its persistence Was rated as follows:

When the suds disappeared in less than five minutes after starting the operation of the washing machine, the foam persistence was given a rating of 1. When the suds disappeared in an interval of time equal from 5 to 10 minutes, the foam persistence was assigned a rating of 2. When the suds disappeared in a period of time from 10 to 20 minutes, its persistence was assigned a rating of 3. Whenever the suds lasted 20 minutes under the conditions of agitation, but the height of the suds on the surface of the liquid in the bowl of the machine was lower than one inch, a rating of 4 was assigned to the persistence. When, after 20 minutes of operation, the height of the suds above the surface of the liquid was from 1 to 3 inches, a rating of 5 was assigned to the foam persistence. A rating of 6 was given to the persistence of the suds which stayed at a height of 3 to 6 inches after 20 minutes of operation. Finally, a maximum rating of 7 was assigned to the persistence of suds which remained higher than 6 inches above the surface of the liquid after 20 minutes of operation.

TABLE I Foam Evaluation Data Bench test Washing machine Cit-Ola Cir- 15 Test alkyl a1 1 run sulfate, benzene p-Lauro-phenol, parts'by wt. Foam height No. parts by sulfonate, (mm.)

wt, parts by Foam Foam 50 300 wt. stability quality p.p.m. p.p.m.

After After 1 min. 15 min.

1 10 7 7 2 H 10 10 7 4 3 5 7 5 4 3 17 7 2 5 10 10 4 3 0 0 17 1 1 7 0 3 4 S 20 0 2 48 39 Good 9 10 10 2 (p-stearophenol) 35 8 Ioor 10... 10 10 2 (o-laurophenol) 11..." 10 10 2 (lauryl alcohol) o 12.. 10 10 2 (p-aeylphcnol mixture derived from 74 pressed stearic acid"). 13... 10 10 2 (p-caprophenol) 85 14"... 10 10 2 (p-myristophenol)" 78 15... 10 10 2 (p-ncylphenol mixture 80 nut oil fatty acids (Ca- 18)).

Composition of pressed stearic acid": 67% by weight of palmitic acid, 29% by weight of stearic acid, 4% by weight of olcie acid.

The results shown in Table I clearly point out that foam persistenc is improved by the presence of the para-n-acylphenol additive. Thus, the foam of solutions formed with hard Water (300 p. p. m., Ca-Mg hardness) solutions containing two parts by weight of para-laurophenol is more persistent than the foam of similar hard water solutions containing an equal amount of a wellknown foam promoter and stabilizer such as lauryl alcohol (washing machine test #1 vs. #10). The results of the bench tests also show that para-acylphenols having more than 16 carbon atoms in the acyl group are inefficient as promoters of stable foams of better quality at the temperatures tested (120 F.). The foams produced by dilute aqueous solutions of the detergent formulations of our invention, which contain the paran-acylphenol additive, display a flexible texture which resembles that of the foams of the better fatty acid soaps. They are light in color and ar constituted by small-sized bubbles agglomerated to a cream-like consistency. The excellent stability and quality of the foams are particularly evident with the formulations containing C12-C14 p-acylphenols as foam-improving agents. These foams impart the same creamy, dense-bodied feeling as the conventional soap suds familiar to housewives. It is to be noted that the presence of para-acylphenols in the detergent formulations of our invention does not adversely affect the washing efficiency (detergency) of the wash solutions prepared with these formulotions.

Detergency of wash solutions employed in the aforedescribed bench and washing machine tests was compared with that of wash solutions of well-known built synthetic detergent formulations of the trade, which contained 10% by weight of sodium Ctr-C18 monoalkyl benzene sulfonate and 10% by weight of sodium chi-C18 alkyl sulfate, the remainder being sodium sulfate and phosphate builders. Comparative runs were carried out in a launderometer, employing cotton swatches soiled with an oily-type soil at a temperature of about 140 F. The solutions were prepared with soft water (50 p. p. m. of Ca-Mg hardness) and hard water (300 p. p. m. of Ca- Mg hardness) in different concentrations ranging from 0.05 to 0.2%. A whiteness level obtained with a 0.4% concentration of a well-known fatty acid household soap in hard water (300 p. p. m.) was assumed as the standard of detergency and assigned a rating of 1.00. The results of these detergency runs are shown in Table II.

lotion (test run No.1ofTablcI). 0.72 0.98 1.04 1.06 0.32 0.45 1.08 1.08 Comparison formulation 1.05 1.11 1.08 1.08 0.97 0.92 0.08 1.14

In addition, several series of parallel bench and washing machine tests were effected using dilute aqueous solutions (0.1 to 0.4% concentration) of detergent formulations prepared in the same manner as the solutions of the hereinbefore described test series, but employing sodium alkyl sulfates produced by sulfation of aliphatic alcohols derived from coconut oil fatty acids. in these test series satisfactory detergent action and foam persistence, i. e., ample foam volume, good foam quality and excellent persistence (rated from 6 to 7), were achieved even in the absence of the monoalkyl benzene sulfonate admixture from the active organic portion of the formulations employed.

It may be mentioned, in addition, that alkylolamides commonly employed in the art as foam promoters and improvers, e. g., lauric isopropanolamide or lauric ethanolamidc, may be employed, if desired, in the detergent compositions prepared in accordance with our invention. Their presence enhances the soil tolerance thereof, without interfering in any way with the beneficial effects of the para-acylphenol additive on foam persistence in dishwashing and laundering solutions prepared by using these concentrates.

in this specification and in the claims appended thereto, the terms organic detergent component and organic portion of the active detergent component have been purposely employed to stress the distinction between organic active materials and inorganic active materials present in the detergent compositions.

It is to be understood that the aforegiven description and examples are only illustrative of the invention, and that any modification thereof consistent with its spirit and scope are to be included in the terms of the following claims.

We claim:

1. A detergent composition consisting essentially of an active organic detergent component and a foam-improving agent, said active organic detergent component consisting of water-soluble sulfates of normal aliphatic alcohol's derived from hydrogenated tallow fatty acids and containing a major proportion of C18 n-alkyl sulfate, and Water-soluble C12-C1s monoalkyl benzene sulfonates in a weight ratio of sulfate to sulfonate from about 1:1 to about 1:6; and said foam-improving agent being a paraacylphenol characterized by a straight chain of 8 to 16 carbon atoms in its acyl portion and present in the detergent composition in an amount from to 50% by Weight, based on the Weight of said sulfates of normal aliphatic alcohols.

2. A detergent composition consisting essentially of an active organic detergent component and a foam-improving agent, said active organic detergent component consisting of sodium sulfates of normal aliphatic alcohols derived from hydrogenated tallow fatty acids and containing a major proportion of sodium C18 n-alkyl sulfate and sodium C12-C15 monoalkyl benzene sulfonates in a weight ratio of sulfate to sulfonate from about 1:1 to about 1:6; and said foam-improving agent being paranlaurophenol present in the detergent composition in an amount from 5 to 50% by weight, based on the Weight of said sulfates of normal aliphatic alcohols.

3. A built detergent formulation consisting essentially of 10 to by weight of the detergent composition defined in claim 1, the remainder to make 100% by weight being essentially water-soluble inorganic electrolyte salt builders for said detergent composition.

4. A detergent composition consisting essentially of an active organic detergent component and a foarn improving agent, said active organic detergent component con- 'sisting of sodium sulfates of normal aliphatic alcohols derived from hydrogenated t-allow fatty acids and containing from to by Weight of sodium C18 n-alkyl sulfate, and sodium C12-C15 monoalkyl benzene sulfonates in a weight ratio of sulfate to sulfonate from about 1:1 to about 1:6; and said foam-improving agent being a para-acylphenol characterized by a straight chain of 8 to 16 carbon atoms in its acyl portion and present in the detergent composition in an amount from 5 to 50% by Weight, based on the Weight of said sulfates of normal aliphatic alcohols.

References Cited in the file of this patent UNITED STATES PATENTS 2,213,477 Steindorif Sept. 3; 1940 2,477,383 Lewis July 26, 1949 FOREIGN PATENTS 511,341 Belgium Nov. 12, 1952 

1. A DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF AN ACTIVE ORGANIC DETERGENT COMPONENT AND A FOAM-IMPROVING AGENT, SAID ACTIVE ORGANIC DETERGENT COMPONENT CONSISTING OF WATER-SOLUBLE SULFATES OF NORMAL ALIPHATIC ALCOHOLS DERIVED FROM HYDROGENATED TALLOW FATTY ACIDS AND CONTAINING A MAJOR PROPORTION OF C18 N-ALKYL SULFATE, AND WATER-SOLUBLE C12-C15 MONOALKYL BENZENE SULFONATES IN A WEIGTH RATIO OF SULFATE TO SULFONATE FROM ABOUT 1:1 TO ABOUT 1:6; AND SAID FORAM-IMPROVING AGENT BEING A PARAACYLPHENOL CHARACTERIZED BY A STRIGHT CHAIN OF 8 TO 16 CARBON ATOMS IN ITS ACYL PORTION AND PRESENT IN THE DETERGENT COMPOSITION IN AN AMOUNT FROM 5 TO 50% BY WEIGHT, BASED ON THE WEIGHT OF SAID SULFATES OF NORMAL ALIPHATIC ALCOHOLS. 